Question

$pH$ of a solution produced when an aqueous solution of $pH=6$ is mixed with an equal volume of an aqueous solution of $pH=3$ is:
$(\text{Given}:\log 5.005=0.6994)$

• A. $4.5$
• B. $4.0$
• C. $4.3$
• D. $3.3$

Answer 1

The correct option is D $3.3$

In the final solution, $\left[H^{+}\right]=\frac{({10}^{-6}+{10}^{-3})}{2}$
$=0.5005\times {10}^{-3}=5.005\times {10}^{-4}pH=-\log \left[H^{+}\right]=-\log (5.005\times {10}^{-4})=4-0.6994\approx 3.3$